found in cells a foot beneath the surface.
As shown in the cut, those cells situated lowest down seem to be the
last to have been made, while the eggs laid in the highest are the first
to hatch, and the larvae disclosed from them, the first to change to
pupae. Four days later the pupae of Cuckoo bees (Nomada) were found in the
cells. No Andrenas were seen flying about at this time.

On the 24th of August, to be still very circumstantial in our narrative
though at the risk of being tedious, three burrows were unearthed, and
in them three fully formed bees were found nearly ready to leave their
cells, and in addition several pupae. In some other cells there were
three of the parasitic Nomada also nearly ready to come out, which
seemed to be identical with some bees noticed playing very innocently
about the holes early in the summer.

On the last day of August, very few of the holes were open. A number of
Oil beetles were strolling suspiciously about in the neighborhood, and
some little black Ichneumon flies were seen running about among the
holes.

During mid-summer the holes were found closed night and day by clods of
earth.

The burrow is sunken perpendicularly, with short passages leading to the
cells, which are slightly inclined downwards and outwards from the main
gallery. The walls of the gallery are rough, but the cells are lined
with a mucous-like secretion, which, on hardening, looks like the
glazing of earthenware. This glazing is quite hard, and breaks up into
angular pieces. It is evidently the work of the bee herself, and is not
secreted and laid on by the larva. The diameter of the interior of the
cell is about one-quarter of an inch, contracting a little at the mouth.
When the cell is taken out, the dirt adheres for a line in thickness, so
that it is of the size and form of an acorn.

The larva of Andrena (Fig. 29) is soft and fleshy, like that of the
Honey bee. Its body is flattened, bulging out prominently at the sides,
and tapering more rapidly than usual towards each end of the body. The
skin is very thin, so that along the back the heart or dorsal vessel may
be distinctly seen, pulsating about sixty times a minute.

Our cut (Fig. 28, _a_) also represents the pupa, or chrysalis, as seen
lying in its cell. The limbs are folded close to the body in the most
compact way possible. On the head of the semi-pupa, _i.e._, a transition
state between the larva and pupa, there are two prominent tubercles
si